Status and operation of the Linac4 ion source prototypes.

Area of Science:

• Particle Accelerators
• Plasma Physics
• Ion Source Technology

Background:

• CERN's Linac4 requires high-intensity negative hydrogen ion (H(-)) beams.
• Development of reliable and efficient H(-) ion sources is critical for accelerator performance.

Purpose of the Study:

• To present the design and experimental results of two H(-) ion source prototypes for CERN's Linac4.
• To evaluate the performance of RF-sustained plasma heating and beam extraction.

Main Methods:

• Utilized pulsed hydrogen injection, 2 MHz RF-plasma heating (capacitive ignition, inductive sustain), and pulsed high voltages.
• Employed optical emission spectroscopy and photometry to analyze plasma characteristics.
• Designed a cesiated volume source for enhanced performance.

Main Results:

• Achieved a 45 keV H(-) beam with a current of 16-22 mA from the volume source.
• Successfully commissioned the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.
• Demonstrated the operational principles of RF-sustained plasma and preliminary plasma diagnostics.

Conclusions:

• The developed H(-) ion source prototypes meet the requirements for Linac4 commissioning.
• The experimental results validate the RF-plasma heating approach and diagnostic techniques.
• The cesiated source design shows promise for future high-intensity ion beam applications.